GN: Implement is_lsan, is_tsan and is_msan.

build/config/BUILDCONFIG.gn

Index: build/config/BUILDCONFIG.gn
diff --git a/build/config/BUILDCONFIG.gn b/build/config/BUILDCONFIG.gn
index ee32088dfcdee63f409cff05760d4a8261d92680..1cd3fd93e264f3d05b9a79175b82c4e9032d60d7 100644
--- a/build/config/BUILDCONFIG.gn
+++ b/build/config/BUILDCONFIG.gn
@@ -77,15 +77,23 @@ declare_args() {
 
   # Compile for Address Sanitizer to find memory bugs.
   is_asan = false
+  asan_blacklist = "//tools/memory/asan/blacklist.txt"

[brettw, 2015/05/19 22:54:27]

Please don't add any more args to this file. I'm adding some advice in:
https://codereview.chromium.org/1125033004
on what to do instead. Please read that and let me know if it's clear.

Also, do these things really need to be parameterized? Does anybody actually set
the blacklist file from outside the build?

[Sam McNally, 2015/05/20 01:07:21]

I think it's clear for args used by a subset of the build, but it doesn't cover
args that BUILDCONFIG.gn depends on. Specifically, if is_asan and friends were
moved into a sanitizers.gni, how could is_clang and symbol_level be set
depending on those args?
As far as I can tell nothing is setting custom blacklist files. Removed them.
msan_track_origins is a documented option.

 
   # Compile for Leak Sanitizer to find leaks.
   is_lsan = false
 
   # Compile for Memory Sanitizer to find uninitialized reads.
   is_msan = false
+  msan_blacklist = "//tools/msan/blacklist.txt"
+
+  # Track where uninitialized memory originates from. From fastest to slowest:
+  # 0 - no tracking, 1 - track only the initial allocation site, 2 - track the
+  # chain of stores leading from allocation site to use site.
+  msan_track_origins = 2
 
   # Compile for Thread Sanitizer to find threading bugs.
   is_tsan = false
+  tsan_blacklist = "//tools/memory/tsan_v2/ignores.txt"
 
   if (current_os == "chromeos") {
     # Allows the target toolchain to be injected as arguments. This is needed
@@ -373,6 +381,9 @@ if (symbol_level == -1) {
   # Mac and Windows have them separate, so in Release Linux, default them off.
   if (is_debug || !is_linux) {
     symbol_level = 2
+  } else if (is_asan || is_lsan || is_tsan || is_msan) {
+    # Sanitizers require symbols for filename suppressions to work.
+    symbol_level = 1
   } else {
     symbol_level = 0
   }